BACKGROUND: Paediatric patient reported experience measures (pPREMs) can help children's voices be heard to evaluate and improve healthcare delivery. However, no standardised child-completed pPREM has been co-designed with children and validated in Australia. This research aimed to test the content validity of a co-created pPREM using an iterative, participatory approach with children.

METHODS: 21 children aged 6-11 years were recruited across four Australian hospitals. Children participated in online cognitive interviews to evaluate pPREM items and rating scales (using 'stars' or 'smiley faces') for their understandability, usability, relevance and importance related to their needs in hospital. Framework analysis was conducted iteratively, with items refined after the first round of interviews based on children's feedback.

RESULTS: Most (n=20; 95%) children understood the instructions. After nine interviews, two items were revised: 'Someone I knew could stay with me' changed to 'Family and friends could be with me' and 'I was able to talk to other patients', to 'I was able to talk to other kids in hospital'. Following these revisions, all children understood most (13 of 18=72%) items. In the remaining five items, some phrases, such as 'Care and treatment', were not easily understood, and items were edited according to children's feedback. Most children (n=14; 67%) preferred the 'smiley faces' rating system, and 83% (n=15) reported the number of questions as the right amount. Children generally found all items important, although some items did not apply to all and a 'Does not apply to me' response option was added.

CONCLUSIONS: Children aged 6-11 years can meaningfully engage with a co-designed pPREM. Cognitive interviews and an iterative approach helped identify and rectify comprehension issues. It is feasible to involve children in the design of pPREMs and doing so strengthens pPREMs' usability and understandability.